Is Carbon Capture and Storage (CCS) Really So Expensive? An Analysis of Cascading Costs and CO2 Emissions Reduction of Industrial CCS Implementation on the Construction of a Bridge

Carbon capture and storage (CCS) is an essential technology to mitigate global CO2 emissions from power and industry sectors. Despite the increasing recognition of its importance to achieve the net-zero target, current CCS deployment is far behind targeted ambitions. A key reason is that CCS is often perceived as too expensive. The costs of CCS have however traditionally been looked at from the industrial plant perspective, which does not necessarily reflect the end user’s one. This paper addresses the incomplete view by investigating the impact of implementing CCS in industrial facilities on the overall costs and CO2 emissions of end-user products and services. As an example, we examine the extent to which an increase in costs of raw materials (cement and steel) due to CCS impacts the costs of building a bridge. Results show that although CCS significantly increases cement and steel costs, the subsequent increment in the overall bridge construction cost remains marginal (∼1%). This 1% cost increase, however, enables a deep reduction in CO2 emissions (∼51%) associated with the bridge construction. Although more research is needed in this area, this work is the first step to a better understanding of the real cost and benefits of CCS.


27
corresponds to the cradle-to-gate CO 2 emissions associated with bridge construction (t CO 2 ); 28 is the amount of cement (t cement ); , 29 are upstream CO 2 emissions related to the raw material extraction and their transport to the production facility (t CO 2 /t steel );

41
are CO 2 emissions of steel production (t CO 2 /t steel ); , 42 are transport emissions of steel to bridge construction site (t CO 2 /t steel ). ,

43
It is worth noting that HRC is converted to several products and forms of steel (e.g., wire, rod, and 44 structural steel) utilizing some tasks that emit CO 2 [1]. These emissions ( ) were added to the , 45 CO 2 emitted by the steel production plant as follows: where,

48
are CO 2 emissions of the steel product (t CO 2 /t steel ); , 49 are CO 2 emissions of the HRC-steel plant (t CO 2 /t steel ); , 50 is the amount of steel obtained from one tonne of HRC (t HRC /t steel ).

51
It is assumed that one tonne of HRC is converted into one of any steel products, i.e., . = 1 52 S4 53 The upstream emissions ( were aggregated by taking into account all the emissions related to ) 54 raw materials extraction and their transport to primary/intermediate production facilities as follows: where,

57
are CO 2 emissions related to raw materials extraction in the upstream supply chain; , 58 are transport emissions related to raw materials in the upstream supply chain.
, 59 60     CO 2 avoided -47% [7] Conversion of HRC into steel (kg CO2 /t steel ) 300 300 [1] S6 74 75 was calculated directly based on . The delivery cost, , was obtained based on the transport cost 119 model. The fixed and plant costs are obtained using their remaining percentage of share in the 120 concrete cost. While estimating , the transport costs from the cement plant to concrete facility 121 were included in the cost of cement. Except for cement cost, all other cost components remain 122 unchanged without and with CCS implementation.

124
The steel cost ( was obtained by summing the production cost of steel and delivery costs as ) 125 shown below, where,

128
is the production cost of HRC ( /t HRC ); € 129 is the relative cost factor represented as the ratio of the steel product price ( /t steel ) and the HRC € 130 price ( /t HRC ); € 131 is the steel delivery cost from the steel plant to the construction site ( /t steel ). €

132
The HRC produced in the steel mill plant is converted into several products of steel (e.g., wire, rod, 133 and structural steel) by utilizing some additional tasks. A relative cost factor ( is used to represent ) 134 the differences in each steel product cost based on production costs without CCS [1]. Note that 135 and was used for converting HRC into wire/rod forms of steel and structural steel, = 1 = 1.23 136 respectively [1]. The production cost of HRC with and without was obtained from the literature [7].

138
The cost data for cement and steel plants without and with CCS implementation were retrieved 139 from the literature [3,7] and are provided in Tables S7 and S8. The total production costs were 140 obtained based on annualised CAPEX and operating costs as follows: Production cost ( € t product ) = annualised CAPEX ( € t product ) + fixed OPEX ( € t product ) + variable OPEX ( € t product )

143
The annualised CAPEX and fixed OPEX costs from previous studies were directly updated to € 2018 144 using Chemical Engineering Plant Cost Index (CEPCI). The variable operating costs include raw 145 material costs, energy costs, and other miscellaneous costs. In the cement plant, the variable 146 operating costs are incurred due to the consumption of raw meal, coal, electricity, ammonia, and 147 other miscellaneous expenses. The variable operating costs in the steel plant are due to the 148 consumption of iron ore, coal, natural gas, scrap and ferroalloys, fluxes, and other consumables. 149 While some of these cost components were directly updated to € 2018 based on CEPCI, other 150 components such as iron ore, coal, natural gas, and electricity typically have a wide range of price 151 fluctuations over years. To provide a more accurate estimate, the cost contributions from coal and 152 electricity consumption in the cement plant were calculated based on annual coal and electricity 153 consumption and their prices in 2018 (provided in Table S9). Similarly, iron ore, coal, and natural 154 gas costs in the steel plant were estimated based on their annual consumption and unit prices in 155 2018. The annual consumption of raw materials is provided in Tables S1 and S2. For CCS scenarios, 156 CO 2 transport and storage costs (e.g., 10 €2018/tCO2) are also included in the variable operating costs.

S2.1. Cement and subsequent concrete production 170
The CO 2 emissions and cost estimation presented in Tables S11and S12 are expressed per tonne of 171 cement and per m 3 concrete, respectively. Moreover, the calculations are based on 340 kg of cement 172 is required to produce 1 m 3 of concrete [6].

S2.2. Steel and subsequent steel products production 181
The CO 2 emissions and cost estimation presented in Table S13 are expressed per tonne of HRC or 182 steel. S11 183 184